Chinch Bugs, Their Damage and Elimination

Chinch bugs are most damaging to St. Augustine grass. You may see them on
grasses such as zoysia, Bermuda, and centipede, but infestations usually occur where high
populations have built up on St. Augustine grass. Adult chinch
bugs are about one-fifth of an inch long and black with white wings folded over their
backs. The insect mates early in the season when the temperature reaches 70 degrees
Fahrenheit. The female lays eggs on roots, stems, leaves, leaf sheaths or crevices
in nodes and other protected places. Eggs are laid over a 2 to 3 week period, with
one female laying as many as 500 eggs.

The young chinch bugs ( called nymphs) develop into adults in four to six
weeks. Nymphs are yellow upon hatching but soon turn red and have a light colored
band across their abdomens. With each molt, nymphs more closely resemble the adults.
There are 2 to 4 generations per year.

The chinch bugs insert their slender beak into the grass and suck the plant
juices. As the chinch bug sucks the plant juices, it releases a toxin that causes
yellowish to brownish patches in turf. Typical injury appears as spreading patches
of brown, dead grass. This pest is a sunshine-loving insect and seldom attacks grass
in a dense shady area. Discolored areas caused by chinch bug feeding that are in
open sunlight several hours daily may be "hot spots" for chinch bug damage.
Most homeowners will first notice dead patches of grass along a driveway, curb,
sidewalk or foundation of the home, due to the heat emitted from such objects.

Because they can fly, it is difficult to keep an area free of chinch bugs if
they are emerging from neighboring lawns, golf courses or nearby croplands.

Scout turf on sunny days by slowly sliding your foot through the sod and
watching for the bugs to crawl across your shoe. You can also determine infestations by
using a large coffee can or gallon can with both ends removed. Press one end of the can
about 2 or 3 inches into the soil, fill with soapy water, and watch for about 5 minutes.
If chinch bugs are present, they will float to the surface. (This test will also bring
molecrickets to the surface) It is very important to check areas where the yellowish spots
and the green grass meet in several different locations.

Chinch bugs have become resistant to almost every pesticide used to control
them. They were even resistant to DDT in the early 1950s. Of the many
insecticides labeled for chinch bug elimination, there are two that stand out above the
rest: Talstar (which contains
Bifenthrin) and Acephate. For the past several years, Acephate had been the best overall
performer in eliminating chinch bugs in lawns, giving better control than other products
being used by professionals and homeowners alike. However, Talstar has suddenly become the star performer in
eliminating lawn and turf pests such as molecrickets,
ants and chinch
bugs.

For best results, wet turf thoroughly with water before applying an
insecticide. Treat the entire area evenly and thoroughly. Wet the area with water again
after applying the insecticide. Where chinch bug infestations are heavy, re-treat the area
in 2 weeks to kill recently hatched insects, unless you are treating with Talstar.
In this case, repeat applications may not be necessary.

Talstar liquid
concentrate should be applied through a hose end sprayer at the rate of 1/2 ounce per
1000 square feet. Talstar granules
should be applied at the rate of 25 pounds per 1/4 acre and irrigated immediately after
application.

Acephate should be
applied through a hose end sprayer at the rate of 1 pound per 1/4 acre in sufficient
water.

Thatch removal is important for eliminating conditions favorable for chinch bug
survival. Maintaining adequate moisture will increase the tolerance of turf to
feeding damage and will promote beneficial fungi that attack chinch bugs. Low
nitrogen fertilization slows chinch bug reproduction although the lawns regularly attacked
by these insects (St. Augustine) are heavy feeders and prefer more fertilizer than other
turf grasses. Consult your local county
extension office about feeding your St. Augustine grass.